Treatment of pain is of great importance in medicine. There is a worldwide need for active pain therapies. The urgent need for action for target-orientated treatment of chronic and non-chronic states of pain appropriate for the patient, meaning successful and satisfactory pain treatment for the patient, is documented in the large number of scientific works which have recently been published in the field of applied analgesia and fundamental research on nociception. Treatment of epilepsy is also of great importance in medicine.
The cyclic GABA analog gabapentin is a clinically tested antiepileptic having an anticonvulsive action. Gabapentin moreover shows further interesting and medically relevant properties, in particular as an analgesic. Gabapentin is also prescribed for migraine and bipolar disorders as well as hot flashes (e.g. in the postmenopause) by doctors performing treatment (M. Schrope, Modern Drug Discovery, September 2000, p. 11). Other indications in which gabapentin shows a therapeutic potential have been identified during human studies and in clinical use (J. S. Bryans, D. J. Wustrow; “3-Substituted GABA Analogs with Central Nervous System Activity: A Review” in Med. Res. Rev. (1999), p. 149-177). The action of gabapentin is listed in detail in this review article. Thus, gabapentin is active in the treatment of chronic pain and behavioral disturbances. There are listed in particular: anticonvulsives and antiepileptic actions, use against chronic, neuropathic pain, in particular thermal hyperalgesia, mechanical allodynia and cold allodynia. It furthermore acts successfully against neuropathy caused by nerve damage, in particular precisely neuropathic pain, and also inflammatory and postoperative pain. Gabapentin is also successful with antipsychotic effects, in particular as an anxiolytic. Further indications which have been investigated include: amyotrophic lateral sclerosis (ALS), reflex sympathetic dystrophy (RSD), spastic paralysis, restless leg syndrome, treatment of symptoms and pain caused by multiple sclerosis, acquired nystagmus and treatment of the symptoms of Parkinson's disease, of painful diabetic neuropathy and of psychiatric disorders, e.g. bipolar disorders, mood swings and manic behaviour. The use of gabapentin was also successful on erythromelalgic pain, postpoliomyelitis pain, trigeminal neuralgia and postherpetic neuralgia (Bryans and Wustrow (1999), loc. cit.). The general activity in neurodegenerative diseases is generally known and can also be seen from the review article mentioned, with the aid of the examples. Such neurodegenerative diseases are e.g. Alzheimer's disease, Huntington's disease, Parkinson's disease and epilepsy. The activity of gabapentin on gastrointestinal damage is also known.